AB0534 PROSPECTIVE STUDY OF 24 MONTHS OF EVOLUTION OF A COHORT OF PATIENTS WITH RHUPUS
Authors: I. Martínez Cordellat, C. Pávez Perales, S. Leal Rodriguez, A. V. Huaylla Quispe, C. Riesco Barcena, L. Mas Sanchez, P. Muñoz Martinez, I. Cánovas Olmos, M. De la Rubia Navarro, J. J. Fragío Gil, L. Gonzalez Puig, E. Grau García, J. Ivorra Cortés, C. Nájera Herranz, R. Negueroles Albuixech, E. Vicens Bernabeu, J. E. Oller Rodríguez, F. Ortiz-Sanjuán, J. A. Román Ivorra
Journal: Annals of the Rheumatic Diseases (2022)

Background Rhupus syndrome (RhS) is a rare combination of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Different studies describe cases of RhS with more frequent initial clinical manifestations in the form of erosive arthritis and the presence of rheumatoid factor (RF) and/or anti-CCP, with later manifestations of SLE appearing. RhS has a low prevalence and it is useful to know the clinical characteristics of the patients and their evolution over time, since their treatment and clinical management differ from those who present RA or SLE in isolation. Objectives Our objective was to study the clinical, analytical and therapeutic evolution of our cohort of patients with Rhupus. Methods Prospective study of a cohort of patients with Rhupus during 2020-2021 with systematic review of electronic records for the analysis of clinical, analytical and therapeutic parameters throughout follow-up. Results Nine patients with RhS (88.9% women) who met SLICC 2012 criteria for SLE and ACR 2010 for RA were included. The mean age was 62.7 (45-86) years. During follow-up, the death of one case due to metastatic pulmonary neoplasia was verified, as well as the incorporation of a new patient in the study population. In 4 cases, RA was the first diagnosis, with a mean evolution of 6.25 years until the diagnosis of SLE. On the contrary, in 5 cases SLE was the first diagnosis with a mean evolution of 7.2 years until the diagnosis of RA. Photosensitivity and arthritis were the predominant clinical manifestations. One patient presented rheumatoid nodules in both elbows and 2 patients presented symptoms of serositis in the form of pleuro/pericarditis. No cases of renal or neurological involvement were recorded. Clinically, the patients have remained stable, presenting joint manifestations as the predominant clinic. Regarding the serological evolution, 8 patients presented positive RF at the beginning of the study, 3 of them becoming negative during follow-up. Likewise, the presence of ACPA was positive in 6 patients, maintaining this percentage at the present time. On the other hand, the ANA were positive at the beginning in all the patients, with ANA becoming negative in 5 of them. Antiphospholipidic antibodies were positive in 2 patients, however none of them developed antiphospholipidic syndrome.. 4 patients were treated with biological drugs/JAK inhibitors (1 abatacept, 1 rituximab, 1 baricitinib and 1 tofacitinib) with a favorable response. Conclusion The analysis of our cohort continues to show that, unlike other series, 44.4%% of RhS cases begin with seropositive polyarticular arthritis. 55.6% of these start with manifestations compatible with SLE, in the form of hematological, cutaneous and serological alterations, and these show a more prolonged progression to develop polyarticular involvement. Therefore, a diagnosis of RhS continues to be reached earlier in patients who present with symptoms of RA. 37.5% of patients had a negative RF, maintaining ACPA + in all of them. ANA were negative in 55%. Neither of the 2 patients with anti PL Ab developed APS. Clinically, joint manifestations in the form of arthralgia of small joints were the predominant clinic. In general, the evolution has been favourable. Four patients were refractory to treatment with cDMARDs, requiring the use of biological drugs/JAK inhibitors with good response. Disclosure of Interests None declared